TEHRAN, April 16 (AFP) - The convicted serial killed of 16 prostitutes in city of Mashhad in 2000 and 2001 was hanged at dawn on Wednesday, IRNA reported. Saeed Hanai, who confessed to killing women ranging in age from 20 to 50 and all with drugs and prostitution records, is to be executed inside Mashhad prison. The serial killer strangled his victims with a scarf before abandoning their bodies around the northeastern city. Prostitution, a thriving industry under the former shah but banned after the 1979 Islamic revolution, has been making a comeback as Iran experiences unemployment and economic woes....